Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

+ References+ Details

Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

+ References+ Details

Fair Value Measurements (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Assets:
Commodity derivatives	$ 85
Liabilities:
Commodity derivatives		87
Recurring basis [Member]
Assets:
Commodity derivatives	85
Liabilities:
Commodity derivatives		87
Recurring basis [Member] \| Level 1 [Member]
Assets:
Commodity derivatives
Liabilities:
Commodity derivatives
Recurring basis [Member] \| Level 2 [Member]
Assets:
Commodity derivatives	85
Liabilities:
Commodity derivatives		87
Recurring basis [Member] \| Level 3 [Member]
Assets:
Commodity derivatives
Liabilities:
Commodity derivatives